Safety precautions when making nitric acid....

[Teck]

I have a question: I've made nitric acid once before. But I was wondering about safety precautions when handling it. Is it always a good habit of waring a chemical respirator when handling, pouring and making RDX? I read that the fumes from the acid destroy the lungs. When I work with it I usually use a small fan that sits on the counter and blows the dust fumes of whatever Im working with. But reading the Nitric acid safety sheet kinda got me worried.

[Pu239 Stuchtiger]

When I'm working with nitric acid, I follow the "if you can smell it, the air concentration is dangerously high" rule. Of course, that rule can't be used for everything.

(edit: typo)

<small>[ April 19, 2002, 10:14 PM: Message edited by: Pu239 Stuchtiger ]</small>

[vulture]

The nasty thing about HNO3 vapours is that they are only visible under a certain angle to a light source. This got me into trouble once. A fan will get damaged by nitric acid vapours.

HNO3 vapours aren't that bad, they make you feel sick and cause a severe headache (personal experience <img border="0" title="" alt="[Wink]" src="wink.gif" /> ) but the NO2 which is formed when heating HNO3 or by reaction HNO3 with Fe and other heavier metals is highly toxic. NO2 can however be detected easily by it's brownish red color.

Watch it when adding conc. sulfuric acid to HNO3, because this will dehydrate it and HNO3 vapours will start to evolve because the conc. goes above 70%.

[Arkangel]

Last time I asked a question about concentrating a chemical, I was rightly toasted for asking about something already in discussion, but I've been searching the forum quite a bit today, and have not found anything that really helps. Feel free to toast me again, but point me in the right direction please?

I'm looking to order some nitric acid soon (quite a lot actually, if anyone in the UK is interested in me decanting some) but have 60% or 70% to choose from.

Mega's lab for RDX states 100% along with my hexamine, but how would I get it to that concentration, OR is there a process for 70% with Hexamine?

[mongo blongo]

Distill it with conc H2SO4.The H2SO4 absorbs the water.

[Arkangel]

So along the same lines as distilling from a solution of a nitrate and Conc H2SO4 as described in NBK's thread on synthesis of nitric acid I guess? Methinks I will have to get a decent distillation setup before I attempt it.

And the RDX lab will not work with 70%?

[mongo blongo]

With 70% HNO3 you will get little or no yield.
If you don't have a distillation apparatus then you could try solvent extraction with Dichloromethane and H2SO4.